问题
解答题
现规定
|
答案
由题意得:
=(xy-3x2)-(-2xy-x2)+(-2x2-3)-(-5+xy)xy-3x2 -2xy-x2 -2x2-3 -5+xy
=xy-3x2+2xy+x2-2x2-3+5-xy
=2xy-4x2+2.
现规定
|
由题意得:
=(xy-3x2)-(-2xy-x2)+(-2x2-3)-(-5+xy)xy-3x2 -2xy-x2 -2x2-3 -5+xy
=xy-3x2+2xy+x2-2x2-3+5-xy
=2xy-4x2+2.